This invention relates a dry disc brake wherein the interface between the friction pads and the rotating member is sealed from the environment.
Disc brakes are utilized in a variety of braking applications. In particular, disc brakes are utilized in heavy vehicle braking. One known type of disc brake is a xe2x80x9cdryxe2x80x9d disc brake. In a second type known as a xe2x80x9cwetxe2x80x9d disc brake, the brake discs are secured in a sealed chamber carrying a fluid. In a dry disc brake, hydraulic pistons are actuated to engage friction pads with a rotating surface. The engagement of the friction pads and the rotating surface slows rotation of the rotating surface.
A dry disc brake 20 as known in the prior art is shown in FIG. 1. A fixed housing 22 carries a pair of opposed pistons 24. Pistons 24 are supplied with fluid through fluid communication lines 26. The fluid communication lines receive a hydraulic fluid to move the pistons 24 and pads 30 towards a rotating disc 28. A pad 30 is actuated on each side of the disc 28. When the system attempts to brake rotation of the rotating member 28, hydraulic fluid is supplied to the pistons 24 which are forced inwardly, forcing the pads 30 against the rotating member 28. This slows rotation of the rotating member 28. In the embodiment shown in FIG. 1, an open area 32 is defined inwardly of the rotating member 28 and the pad 30.
This open area allows debris to reach the interface between the pads 30 and the rotating member 28. This can affect the braking characteristics of the system. Further, the open area 32 might present sparking issues in certain applications. Finally, the braking force occurs over a limited area on the two sides of the rotating member 28. The heat created by the braking is entirely on the one small rotating member 28 in this prior art system.
In a disclosed embodiment of this invention, the fixed components of a dry disc brake are positioned internally of the rotating components. The rotating components surround the pistons and pads, and seal the interface between the pads and the rotating member from debris, etc. Further, the interface is provided on two discs of the rotating member such that the surface area which carries the braking load is on two separate housing components. Thus, there is twice as much housing surface area for carrying heat away from the braking operation when compared to the prior art. These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.